HCA: Hermit Crab Association

I don’t currently have hermit crabs, but I have another land crab species that is kept in a similar way(just much larger). I know the general recommendation for heating is having a UTH on the side of the tank which I do, but was thinking… wouldn’t it be more natural to have the heat on top facing down? What would the downsides be of taking the UTH and putting it on my lid facing down? I have a mist system and feel the humidity shouldn’t be too hard to keep up. It would also help keep the pools fairly warm when they start getting a little colder during winter. With this, he could burrow as deep as he likes to cool off or come up to get warm as they would in the wild.

Heat rises, so the heat from the UTH would rise up and not sink down into the tank. Some people use heat lamps, but those tend to decrease humidity.

Fair enough, I just read people say that UTH is designed to heat objects in front of it rather than the air. With that thinking I was imagining the top layer could be warm and the crab could come up or burrow to regulate heat better.

Where did you hear that?
In a crab tank, the UTH heats the air.

They are said to utilize infrared which apparently heats objects in front rather than the air so much. Granted, I am no expert on the subject and I’m just repeating what people have said and what they are advertised to do

With crabs, we kind of use the UTH in an 'off label' kind of way. We want to heat the air for crab, which a UTH will do when mounted on the back or side of a tank. For reptiles, they want to use the heat differently, and the UTH is used underneath the tank. But with the amount of substrate we use, it would be a fire hazard under the tank.